Display substrate, method of manufacturing the same, and display device having the same

ABSTRACT

A display substrate includes a switching member, a color filter layer, an inorganic insulation layer and a pixel electrode. The switching member includes a gate line, a data line crossing the gate line, and a thin-film transistor (TFT) electrically connected to the gate line and the data line. The color filter layer is formed on the switching member. The inorganic insulation layer is formed on the color filter layer. The inorganic insulation layer has a hole formed thereon, which exposes a portion of the color filter layer in correspondence with the TFT The pixel electrode is formed on the inorganic insulation layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119 to Korean PatentApplication No. 2007-67535, filed on Jul. 5, 2007 in the KoreanIntellectual Property Office (KIPO), the contents of which are hereinincorporated by reference in their entirety.

BACKGROUND OF THE DISCLOSURE

1. Field of the Disclosure

The present disclosure relates to a display substrate, a method ofmanufacturing the display substrate and a display device having thedisplay substrate. More particularly, the present disclosure relates toa display substrate used for a display device, a method of manufacturingthe display substrate, and a display device having the displaysubstrate.

2. Description of the Related Art

A liquid crystal display (LCD) device includes a thin-film transistor(TFT) substrate, a color filter substrate facing the TFT substrate, anda liquid crystal layer interposed between the TFT substrate and thecolor filter substrate.

The TFT substrate includes a signal line formed on an insulationsubstrate, a TFT and a pixel electrode for independently driving aplurality of pixels. The color filter substrate includes a color filterlayer including a red color filter, a green color filter and a bluecolor filter, and a common electrode facing the pixel electrode of theTFT substrate. There may be a decrease in quality if the TFT substrateand the color filter substrate are misaligned.

An LCD device having a color filter on array (COA) structure, in which acolor filter layer is formed on the TFT substrate, has been developed inorder to mitigate the decrease in quality due to misalignment betweenthe TFT substrate and the color filter substrate.

The TFT substrate having the COA structure may include an inorganicinsulation layer covering the color filter layer in order to preventharmful gas from flowing out of the color filter layer.

When the inorganic insulation layer formed on the color filter layer isharder than the color filter layer, the compressibility of the colorfilter layer corresponding to a contact portion of the column spacer maybe reduced. As a result, the spreadability of liquid crystal moleculesmay be reduced, resulting in the formation of portions of the LCDbetween TFT substrate and the color filter substrate that do not fill upwith liquid crystal molecules. The areas that are not filled with liquidcrystal molecules may produce a reddish defect when that portion or theLCD is in a black state.

SUMMARY OF THE DISCLOSURE

The present disclosure provides a display substrate capable ofincreasing display quality by enhancing compression characteristics of aliquid crystal display (LCD) device having a color filter on array (COA)structure.

The present disclosure also provides a method of manufacturing theabove-mentioned display substrate.

The present disclosure also provides a display device having the displaysubstrate.

In one aspect of the present disclosure, a display substrate includes aswitching member, a color filter layer, an inorganic insulation layerand a pixel electrode. The switching member includes a gate line, a dataline crossing the gate line, a thin-film transistor (TFT) electricallyconnected to the gate line and the data line. The color filter layer isformed on the switching member. The inorganic insulation layer is formedon the color filter layer. The inorganic insulation layer has a holeformed thereon, which exposes a portion of the color filter layer incorrespondence with the TFT. The pixel electrode is formed on theinorganic insulation layer.

In an exemplary embodiment, the inorganic insulation layer may includesilicon nitride (SiNx).

In an exemplary embodiment, the color filter layer may include a redcolor filter, a green color filter and a blue color filter formed incorrespondence with each pixel.

In an exemplary embodiment, the switching member may further include astorage electrode formed from a metal layer for forming the gate line.Here, the color filter layer may have a storage hole formed thereon,which exposes a portion of the TFT layer in correspondence with thestorage electrode.

In an exemplary embodiment, the switching member may further include agate insulation layer and a protective layer. The gate insulation layeris formed on an insulation substrate having the gate line. Theprotective layer is formed on the insulation substrate having the gateline, the gate insulation layer, the data line and the TFT formedthereon. Here, the protective layer, the color filter layer and theinorganic insulation layer may further have a contact hole that exposesa portion of the drain electrode of the TFT.

In an exemplary embodiment of the present disclosure, a method ofmanufacturing the display substrate may include forming a switchingmember on an insulation substrate. The switching member may include agate line, a data line crossing the gate line, and a TFT electricallyconnected to the gate line and the data line. A color filter layer maybe formed on the switching member. An inorganic insulation layer may beformed on the color filter layer, the color filter layer having a holeexposing a portion of the color filter layer in correspondence with theTFT. A pixel electrode is formed on the inorganic insulation layer.

In order to manufacture the switching member, a first metal pattern isformed on the insulation substrate. The first metal pattern may includethe gate line, a gate electrode of the TFT and a storage electrode. Agate insulation layer is formed on the insulation substrate having themetal pattern formed thereon. Then, a second metal pattern is formed onthe gate insulation layer, the second metal pattern including the dataline, and source and drain electrodes of the TFT. A protective layer maybe formed on the insulation substrate having the second metal patternformed thereon.

In order to manufacture the color filter layer, a red color filter, agreen color filter and a blue color filter are formed on the switchingmember. Then, a storage hole and a first contact hole are formed on eachof the red, green and blue color filters. The storage hole may expose aportion of the switching member corresponding with the storageelectrode. The first contact hole may expose a portion of the switchingmember corresponding with the drain electrode.

In order to manufacture the inorganic insulation layer, an inorganicmaterial may be formed on the color filter layer having the storage holeand the first contact hole formed thereon. A hole and a second contacthole may be formed by patterning the inorganic insulation material. Thehole may expose a portion of the color filter layer corresponding withthe TFT. The second contact hole may expose a portion of the switchingmember corresponding with the drain electrode. A third contact hole thatexposes a portion of the drain electrode may be formed through theprotective layer. The second contact hole may be formed on the colorfilter layer coincident with the same process used to form the thirdcontact hole.

In another exemplary embodiment, a display device includes a firstsubstrate, a second substrate, a liquid crystal layer and a columnspacer. The second display substrate faces the first display substrate.The liquid crystal layer is interposed between the first displaysubstrate and the second display substrate. The column spacer isdisposed between the first display substrate and the second displaysubstrate to maintain a cell gap between the first display substrate andthe second display substrate. The first display substrate includes aswitching member, a color filter, an inorganic insulation layer and apixel electrode. The switching member includes a gate line, a data linecrossing the gate line, and a TFT electrically connected to the gateline and the data line. The color filter layer is formed on theswitching member. The inorganic insulation layer is formed on the colorfilter layer. The inorganic insulation layer has a spacer hole formedthereon, which exposes a portion of the color filter layer correspondingwith the column spacer. The pixel electrode is formed on the inorganicinsulation layer.

According to the display substrate described above, the method ofmanufacturing the display substrate and the display device having thedisplay substrate, an inorganic insulation layer corresponding to acolumn spacer is removed, forming a spacer hole, in order to improve thecompression characteristics of the color filter layer. Therefore, theformation of unfilled areas of liquid crystal molecules may be preventedor reduced, and the corresponding display quality defects due to theunfilled areas may be prevented or reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other advantages of the present disclosure will becomereadily apparent by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings wherein:

FIG. 1 is a plan view illustrating a display device according to anexemplary embodiment of the present invention;

FIG. 2 is a cross-sectional view taken along the lines I-I′ in FIG. 1;

FIGS. 3A to 3C are graphs showing compression characteristics of a redcolor filter, a green color filter and a blue color filter when aninorganic insulation layer is formed;

FIGS. 4A to 4C are graphs showing compression characteristics of a redcolor filter, a green color filter and a blue color filter when aninorganic insulation layer is not formed; and

FIGS. 5 to 9 are cross-sectional views illustrating a method ofmanufacturing the first display substrate of FIGS. 1 and 2 in accordancewith an exemplary embodiment of the present invention.

DESCRIPTION OF THE EMBODIMENTS

The invention is described more fully hereinafter with reference to theaccompanying drawings, in which embodiments of the invention are shown.This invention may, however, be embodied in many different forms andshould not be construed as limited to the embodiments set forth herein.Rather, these embodiments are provided so that this disclosure will bethorough and complete, and will fully convey the scope of the inventionto those skilled in the art. In the drawings, the size and relativesizes of layers and regions may be exaggerated for clarity.

It will be understood that when an element or layer is referred to asbeing “on,” “connected to” or “coupled to” another element or layer, itcan be directly on, connected or coupled to the other element or layeror intervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on,” “directly connected to“or “directly coupled to” another element or layer, there are nointervening elements or layers present. Like numbers refer to likeelements throughout. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, components, regions,layers and/or sections, these elements, components, regions, layersand/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer orsection from another region, layer or section. Thus, a first element,component, region, layer or section discussed below could be termed asecond element, component, region, layer or section without departingfrom the teachings of the present invention.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the exemplary term “below” can encompass both anorientation of above and below. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a,” “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Embodiments of the invention are described herein with reference tocross-section illustrations that are schematic illustrations ofidealized embodiments (and intermediate structures) of the invention. Assuch, variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, embodiments of the invention should not be construed aslimited to the particular shapes of regions illustrated herein but areto include deviations in shapes that result, for example, frommanufacturing. For example, an implanted region illustrated as arectangle will, typically, have rounded or curved features and/or agradient of implant concentration at its edges rather than a binarychange from implanted to non-implanted region. Likewise, a buried regionformed by implantation may result in some implantation in the regionbetween the buried region and the surface through which the implantationtakes place. Thus, the regions illustrated in the figures are schematicin nature and their shapes are not intended to illustrate the actualshape of a region of a device and are not intended to limit the scope ofthe invention.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Hereinafter, the present invention will be described in detail withreference to the accompanying drawings.

FIG. 1 is a plan view illustrating a display device according to anexemplary embodiment of the present invention. FIG. 2 is across-sectional view taken along the lines I-I′ in FIG. 1.

Referring to FIGS. 1 and 2, in an exemplary embodiment, a display device100 may include a first display substrate 200, a second displaysubstrate 300, a liquid crystal layer 400 and a column spacer 500. Thesecond display substrate 300 faces the first display substrate 200. Theliquid crystal layer 400 is interposed between the first displaysubstrate 200 and the second display substrate 300. The column spacer500 is disposed between the first display substrate 200 and the seconddisplay substrate 300 to maintain a cell gap between the first displaysubstrate 200 and the second display substrate 300.

The first display substrate 200 may include a first insulation substrate210, a switching member 220, a color filter layer 230, an inorganicinsulation layer 240 and a pixel electrode 250.

The first insulation substrate 210 may include transparent glass and aplastic material.

The switching member 220 may be formed on the first insulation substrate210. The switching member 220 may include a gate line GL, a data line DLand a thin-film transistor (TFT). The switching member 200 may furtherinclude a gate insulation layer 221 and a protective layer 222.

The gate line GL may be formed on the first insulation substrate 210.The gate line GL may be extended along a horizontal direction whenviewed from a plan view.

The gate insulation layer 221 may be formed on the first insulationsubstrate 210 having the gate line GL formed thereon. The gateinsulation layer 221 may include, for example, silicon nitride (SiNx) orsilicon oxide (SiOx).

The data line DL is formed on the gate insulation layer 221. The dataline DL may be extended along a direction that is different from thehorizontal direction so as to cross the gate line GL. The data line DLmay be extended along a vertical direction when viewed from a plan view.The data line DL is electrically isolated from the gate line GL throughthe gate insulation layer 221.

The TFT is electrically connected to the gate line GL and the data lineDL. The TFT may include a gate electrode GE, an active pattern AP, asource electrode SE and a drain electrode DE.

The gate electrode GE is electrically connected to the gate line GL toperform a gate terminal function of the TFT.

The active pattern AP may be formed on the gate insulation layer 221.The active pattern AP may be formed below the source electrode SE, thedrain electrode DE and the data line DL. Alternatively, the activepattern AP may be formed only in a portion that is overlapped with thegate electrode GE.

The active pattern AP may include a semiconductor layer 223 and an ohmiccontact layer 224. The semiconductor layer 223 may perform a role of achannel through which current flows. The ohmic contact layer 224 mayperform a role of decreasing a contact resistance between thesemiconductor layer 223 and the source and drain electrodes SE and DE.For example, the semiconductor layer 223 may include amorphous silicon(a-Si). The ohmic contact layer 224 may include n+ amorphous silicon (n+a-Si) that is formed by implanting n+ impurities at a highconcentration. For example, phosphorous (P) may be implanted into anupper portion of the semiconductor layer 223 to form the ohmic contactlayer 224. The ohmic contact layer 224 may be partially removed so thatthe semiconductor layer 223 is partially exposed.

The source electrode is electrically connected to the data line DL. Thesource electrode SE may be formed on the active pattern AP to perform asource terminal function of the TFT.

The drain electrode DE may be spaced apart from the source electrode SEon the active pattern AP to perform a drain terminal function of theTFT.

The data line DL, the source electrode SE, the drain electrode DE andthe active pattern AP may be patterned through one masking process, sothat an outline of the active pattern AP may be substantially identicalto an outline of the data line DL, the source electrode SE and the drainelectrode DE.

The TFT may be arranged to apply a data voltage applied through the dataline DL to the pixel electrode 250 in response to a gate voltage appliedthrough the gate line GL.

The protective layer 222 is formed on the first insulation substrate 210having the gate line GL, the gate insulation layer 221, the data line DLand the TFT formed thereon. The protective layer 222 may include, forexample, silicon nitride (SiNx) or silicon oxide (SiOx).

The switching member 220 may further include a storage electrode STE.The storage electrode STE may be formed from the same metal layer usedto form the gate line GL. The storage electrode STE may be parallel withthe gate line GL between the gate lines GL adjacent to each other.

The storage electrode STE is opposed to the pixel electrode 250 by thegate insulation layer 221, the protective layer 222 and the inorganicinsulation layer 240 which are interposed therebetween to form a storagecapacitor Cst. Thus, a data voltage applied to the pixel electrode 250through the TFT may be maintained by the storage capacitor Cst duringone frame interval.

The color filter layer 230 may be formed on the switching member 220.The color filter layer 230 may include a red color filter, a green colorfilter and a blue color filter formed in correspondence with each pixel.For example, the red color filter may include an organic composition andred dyes or red pigments, the green color filter may include an organiccomposition and green dyes or green pigments, and the blue color filtermay include an organic composition and blue dyes or blue pigments. Thered, green and blue color filters may be formed on the protective layer222 and may have a uniform pattern. For example, the red, green and bluecolor filters may be sequentially arranged along a horizontal directionor a vertical direction so that one color filter corresponds to onepixel.

The color filter layer 230 may include a relatively high thickness inorder to planarize a surface of the first display substrate 200. Athickness of the color filter layer 230 may have a range of about 2.5 μmto about 3.5 μm. The color filter layer 230 may be formed on the firstdisplay substrate 200, so that organic insulation for planarizing thefirst display substrate 200 may be omitted. Therefore, the lighttransmittance of a liquid crystal display (LCD) device may be increased,and manufacturing costs of the LCD device may be reduced.

The color filter layer 230 may include a storage hole STH exposing atleast one portion of the switching member 200 corresponding to aposition of the storage electrode STE. A distance between the storageelectrode STE and the pixel electrode 250 is decreased through thestorage hole STH, so that the capacitance of the storage capacitor Cstmay be increased.

The inorganic insulation layer 240 may be formed on the color filterlayer 230. The inorganic insulation layer 240 may prevent harmful gasfrom flowing out of the color filter layer 240 and may preventcontamination of the liquid crystal layer 400, so that display qualitymay be enhanced.

The inorganic insulation layer 240 may be formed between the colorfilter layer 230 and the pixel electrode 250. The inorganic insulationlayer 240 may prevent the liquid crystal layer 400 and an alignmentlayer (not shown) disposed on the pixel electrode 250 from directlycontacting the color filter layer 230 through an opening area of thepixel electrode 250. Therefore, the inorganic insulation layer 240 mayprevent harmful gas from flowing out of the color filter layer 230including a photosensitive composition and infiltrating into the liquidcrystal layer 400 through the alignment layer. Furthermore, a chemicalreaction between the color filter layer 230 and the alignment layer maybe prevented.

The inorganic insulation layer 240 may include an inorganic materialhaving low reactivity with organic material in order to prevent harmfulgas from flowing out. For example, the inorganic insulation layer 240may include silicon nitride (SiNx).

The inorganic insulation layer 240 may be formed through a lowtemperature deposition process of about 100° C. to about 250° C. inorder to prevent damage such as through pyrolysis of the color filterlayer 230 including a photosensitive organic composition. For example,the inorganic insulation layer 240 may be formed through a chemicalvapor deposition (CVD) process at a temperature of about 160° C. toabout 180° C. The inorganic insulation layer 240 may be formed with athickness of about 500 Å to about 2,000 Å in order to prevent gas fromflowing out of the color filter layer 230.

The inorganic insulation layer 240 includes a spacer hole SPH exposing aportion of the color filter layer 230. The spacer hole SPH may be formedin a position corresponding to the column spacer 500. Furthermore, thespacer hole SPH is formed on the TFT. For example, the spacer hole SPHmay be formed on a channel portion of the TFT.

When the inorganic insulation layer 240 is disposed between the colorfilter layer 230 and the column spacer 500, the compressibility of thecolor filter layer 230 corresponding to a contact portion of the columnspacer 500 may be decreased. In an exemplary embodiment, the inorganicinsulation layer 240 may include an inorganic material that is harderthan the color filter layer 230 which may include an organic material.Thus, the spreadability of liquid crystal molecules is decreased, sothat portions in which the liquid crystal molecules are not fully filledup may be formed.

In an exemplary embodiment, removing a portion of the inorganicinsulation layer 240 corresponding to the column spacer 500 may increasethe compressibility of the color filter layer 230 corresponding to thecolumn spacer 500, which may help prevent display quality defects due tounfilled areas of liquid crystal molecules.

FIGS. 3A to 3C are graphs showing compression characteristics of a redcolor filter, a green color filter and a blue color filter,respectively, when an inorganic insulation layer is present. FIGS. 4A to4C are graphs showing compression characteristics of a red color filter,a green color filter and a blue color filter, respectively, when aninorganic insulation layer is not present. The graphs as shown in FIGS.3A to 4C will be described in the following Table 1. In FIGS. 3A to 4C,the x-axis denotes the compressibility applied to combine the firstdisplay substrate and the second display substrate, and the y-axisdenotes variation quantities of the red, green and blue color filters inaccordance with the compressibility.

TABLE 1 Inorganic Insulation Variation Recovery Layer Color FilterQuantity (μm) Ratio (%) Formed Red 0.357 72 Green 0.326 74 Blue 0.325 74Not formed Red 0.534 67 Green 0.661 68 Blue 0.926 61

Referring to FIGS. 3 and 4 and Table 1, the results of detectingvariation quantities of the red, green and blue color filters, whichwere detected in accordance with whether or not the inorganic insulationlayer has been formed, minor significant differences existed among thecolor filters. However, the variation quantities of the red, green andblue color filters in the case where the inorganic insulation layer wasformed were higher than those in the case where the inorganic insulationlayer was not formed.

When variation quantities of the red, green and blue color filters areincreased, the second display substrate 300 becomes closer to the firstdisplay substrate 200 so that the spreadability of liquid crystalmolecules may be increased. Thus, unfilled areas of liquid crystalmolecules may be prevented.

Referring back to FIGS. 1 and 2, the pixel electrode 250 may be formedon the inorganic insulation layer 240 corresponding to each pixel. Thepixel electrode 250 may include an optically transparent andelectrically conductive material in order to transmit light. Forexample, the pixel electrode 250 may include indium zinc oxide (IZO),indium tin oxide (ITO) or other suitable materials.

The pixel electrode 250 may be electrically connected to the drainelectrode DE of the TFT. A contact hole CNT may be formed on theprotective layer 222, the color filter 230 and the inorganic insulationlayer 240 in order to electrically connect to the pixel electrode 250and the drain electrode DE. The pixel electrode 250 is electricallyconnected to the drain electrode DE through the contact hole CNT.

The pixel electrode 250 may be opposite to the storage electrode STE byinterposing the inorganic insulation layer 240, the protective layer 222and the gate insulation layer 221 therebetween to form the storagecapacitor Cst in a storage hole area STH of the color filter layer 230.

The pixel electrode 250 may include a predetermined opening pattern fordividing each of pixels into a plurality of domains so as to realize awide viewing angle. The pixel electrode 250 may include a dividedstructure of a main electrode and a sub-electrode that receive differentvoltages. As described, when the pixel electrode 250 is divided into themain electrode and the sub-electrode, two TFTs electrically connected tothe main electrode and the sub-electrode may be formed in each pixel.

The second display substrate 300 may be combined with the first displaysubstrate 200 by interposing the liquid crystal layer 400. The seconddisplay substrate 300 may include a second insulation substrate 310, ablack matrix 320 and a common electrode 330.

The second insulation substrate 310 may include transparent glass and aplastic material.

The black matrix 320 may be formed on the second insulation substrate310. The black matrix 320 is formed to cover at least one column spacer500. Furthermore, the black matrix 320 may be formed corresponding to aportion between the pixel electrodes 250 which corresponds to a boundaryportion of the pixels. That is, the black matrix 320 may be formed inthe boundary portion of the pixels, so that the light transmittance isblocked to enhance the contrast ratio of the LCD device. For example,the black matrix 320 may be formed corresponding with the gate line GL,the data line DL, the storage electrode STE and the TFT.

The common electrode 330 may include an optically transparent andelectrically conductive material in order to transmit light. Forexample, the common electrode 330 may include indium zinc oxide (IZO),indium tin oxide (ITO) or other suitable material. The common electrode330 may include an opening pattern formed thereon in order to realize awide viewing angle.

The second display substrate 300 may include an overcoat layer 340formed between the second insulation substrate 310 and the commonelectrode 330. The overcoat layer 340 may be formed on the seconddisplay substrate 300 in order to planarize a surface of the seconddisplay substrate 300 having the black matrix 320 formed thereon.

The liquid crystal layer 400 may have liquid crystal molecules havingoptical and electrical properties, such as an anisotropic refractiveindex and an anisotropic dielectric constant. When a data voltage isapplied to the pixel electrode 250, electric fields may be generatedbetween the pixel electrode 250 and the common electrode 330 to alter anorientation of the liquid crystal molecules in the liquid crystal layer400. When the orientation of the liquid crystal molecules is altered,the optical transmissivity of the liquid crystal layer is changed, so asto display an image.

The column spacer 500 may be partially formed between the first displaysubstrate 200 and the second display substrate 300 to maintain a cellgap between the first display substrate 200 and the second displaysubstrate 300. The column spacer 500 may be formed at a locationcorresponding to the TFT, so that a decrease of an aperture ratio may beprevented. For example, a column spacer 500 may be formed for groups ofa predetermined number of pixels. For another example, a column spacer500 may be formed in one pixel.

Hereinafter, a manufacturing method of the first display substrate asshown in FIGS. 1 and 2 is explained referring to FIGS. 5 and 9.

FIGS. 5 to 9 are cross-sectional views illustrating an exemplaryembodiment of a method of manufacturing the first display substrate ofFIGS. 1 and 2 in accordance with an exemplary embodiment of the presentinvention.

Referring to FIGS. 1 and 5, a first metal pattern may be formed on thefirst insulation substrate 210, which includes the gate line GL, thegate electrode GE of the TFT and the storage electrode STE. The gateelectrode GE is electrically isolated from the gate line GL and the gateelectrode GE, and the storage electrode STE is electrically isolatedfrom the gate line GL and the gate electrode GE.

The first metal pattern may include a single-layer structure, adouble-layer structure, a multilayer structure, etc. In one example,when the first metal pattern includes the single-layer structure, thefirst metal pattern is formed from a single metallic material such asaluminum (Al), molybdenum (Mo), neodymium (Nd), chromium (Cr), tantalum(Ta), titanium (Ti), tungsten (W), copper (Cu), silver (Ag), etc., or ametal alloy thereof. In another example, when the first metal patternincludes the double-layer structure, a lower metal layer of the firstmetal pattern is formed from relatively high mechanical and chemicalcharacteristics such as aluminum (Al) and an upper metal layer of thefirst metal pattern is formed from a relatively low resistance metalsuch as molybdenum (Mo), a molybdenum alloy or other suitable material.

Referring to FIGS. 1 and 6, the gate insulation layer 221 may be formedon the first insulation substrate 210 having the first metal patternformed thereon so as to cover the first metal pattern. The gateinsulation layer 221 may include, for example, silicon nitride (SiNx) orsilicon oxide (SiOx). The gate insulation layer 221 may have a thicknessof about 1,500 Å to about 2,500 Å.

The second metal pattern may be formed on the gate insulation layer 221.The second metal pattern may include the active pattern AP, the dataline DL, source and drain electrodes of the TFT. The active pattern APand the second metal pattern may be patterned through one mask processusing one mask. When the active pattern AP and the second metal patternare patterned through the one mask process, the active pattern AP may beformed with substantially the same shape as the second metal pattern.That is, the active pattern AP may be formed between the gate insulationlayer 221 and the second metal pattern. Alternatively, the activepattern AP and the second metal pattern may be patterned through twomask processes using two masks different from each other. When theactive pattern AP and the second metal pattern are patterned through thetwo mask processes, the active pattern AP may be partially formed in anoverlapped portion in which the active pattern AP is overlapped with thegate electrode GE when viewed from a plan view of the first displaysubstrate.

The active pattern AP may include a semiconductor layer 223 and an ohmiccontact layer 224. For example, the semiconductor layer 223 may includeamorphous silicon (a-Si), and the ohmic contact layer 224 may include n+amorphous silicon (n+ a-Si). In an exemplary embodiment, n+ impuritiesare implanted into the amorphous silicon layer (a-Si) at a highconcentration to form the ohmic contact layer 224.

The source electrode SE may be electrically connected to the data lineDL, and the drain electrode DE is spaced apart from the source electrodeSE on the gate electrode GE so as to form a channel of the TFT.

The second metal pattern may include a triple-layer structure ofMo/Al/Mo in which a lower molybdenum (Mo) layer, an aluminum (Al) layerand an upper molybdenum (Mo) layer are sequentially deposited.Alternatively, the second metal pattern may include a single-layerstructure or a multilayer structure. When the second metal patternincludes the single-layer structure, the second metal pattern may beformed from a single metallic material such as aluminum (Al), molybdenum(Mo), neodymium (Nd), chromium (Cr), tantalum (Ta), titanium (Ti),tungsten (W), copper (Cu), silver (Ag), or other suitable material, or ametal alloy thereof.

In order to form the TFT, the ohmic contact layer 224 of the channelportion may be removed, corresponding to a gap between the sourceelectrode SE and the drain electrode DE.

Referring to FIGS. 1 and 7, the protective layer 222 may be formed onthe first insulation substrate 210 having the second metal patternformed thereon to cover the second metal pattern. The protective layer222 may include, for example, silicon nitride (SiNx) or silicon oxide(SiOx). Accordingly, the manufacturing process of the switching member220 is completed.

The color filter layer 230 may be formed on the switching member 220.The color filter layer 230 may include a red color filter, a green colorfilter and a blue color filter formed in correspondence with each pixel.The red, green and blue color filters may be sequentially formed so thatone color filter corresponds to one pixel.

The storage hole STH and the first contact hole CNT1 may be formed ineach of the red, green and blue color filters. The storage hole STH mayexpose a portion of the switching member 230 corresponding to thestorage electrode STE. The first contact hole CNT1 may expose a portionof the switching member 230 corresponding to the drain electrode DE.

Referring to FIGS. 1 and 8, an organic material may be deposited on thecolor filter layer 230 having the storage hole STH and the first contacthole CNT1 formed thereon. The organic material may be patterned to formthe inorganic insulation layer 240 having the spacer hole SPH and thesecond contact hole CNT2 formed thereon. The spacer hole SPH may exposea portion of the color filter layer 230 corresponding to the TFT. Forexample, the spacer hole SPH may expose a portion of the color filterlayer 230 corresponding to the channel portion of the TFT. The secondcontact hole CNT may expose a portion of the switching member 220corresponding to the drain electrode DE.

The third contact hole CNT3, which exposes a portion of the drainelectrode DE, may be formed through the protective layer 222. When theprotective layer 222 and the inorganic insulation layer 240 are formedfrom the same silicon nitride (SiNx), the second contact hole CNT2 andthe third contact hole CNT3 may be simultaneously formed. Therefore, thefirst to third contact holes CNT1, CNT2 and CNT3 may define a contacthole CNT that exposes a portion of the drain electrode DE.

Referring to FIGS. 1 and 9, the pixel electrode 250 may be formed on theinorganic insulation layer 240 having the spacer hole SPH and the thirdcontact hole CNT3 formed thereon. The pixel electrode 250 may include anoptically transparent and electrically conductive material in order totransmit light. For example, the pixel electrode 250 may include indiumzinc oxide (IZO), indium tin oxide (ITO), etc. The pixel electrode 250may have a thickness of about 500 Å to about 600 Å.

The pixel electrode 250 may be electrically connected to the drainelectrode DE through the contact hole CNT formed on the inorganicinsulation layer 240, the color filter layer 230 and the protectivelayer 222. Furthermore, the pixel electrode 250 is opposed to thestorage electrode STE by an inorganic insulation layer 240, theprotective layer 222 and the gate insulation layer 221, which areinterposed therebetween to form the storage capacitor Cst.

According to the above display substrate, the method of manufacturingthe display substrate and the display device having the displaysubstrate, an inorganic insulation layer corresponding to a columnspacer is removed, so that compression characteristics of the colorfilter layer may be improved. Therefore, unfilled areas of liquidcrystal molecules may be prevented, and display quality defects due tothe unfilled areas may be prevented.

Although the exemplary embodiments of the present invention have beendescribed, it is understood that the present invention should not belimited to these exemplary embodiments but various changes andmodifications can be made by one ordinary skilled in the art within thespirit and scope of the present invention as hereinafter claimed.

1. A display substrate comprising: a switching member including a gateline, a data line crossing the gate line, and a thin-film transistor(TFT) electrically connected to the gate line and the data line; a colorfilter layer formed on the switching member; an inorganic insulationlayer formed on the color filter layer, the inorganic insulation layerhaving a hole formed thereon, which exposes a portion of the colorfilter layer in correspondence with the TFT; and a pixel electrodeformed on the inorganic insulation layer.
 2. The display substrate ofclaim 1, wherein the inorganic insulation layer comprises siliconnitride (SiNx).
 3. The display substrate of claim 1, wherein the colorfilter layer comprises a red color filter, a green color filter and ablue color filter formed in correspondence with each pixel.
 4. Thedisplay substrate of claim 1, wherein the switching member furthercomprises a storage electrode formed from a metal layer for forming thegate line.
 5. The display substrate of claim 4, wherein the color filterlayer has a storage hole formed thereon, which exposes a portion of theTFT layer in correspondence with the storage electrode.
 6. The displaysubstrate of claim 1, wherein the switching member further comprises: agate insulation layer formed on an insulation substrate having the gateline; and a protective layer formed on the insulation substrate havingthe gate line, the gate insulation layer, the data line and the TFTbeing formed thereon.
 7. The display substrate of claim 6, wherein acontact hole is formed through the protective layer, the color filterlayer and the inorganic insulation layer to expose a portion of thedrain electrode of the TFT.
 8. A method of manufacturing a displaysubstrate, the method comprising: forming a switching member including agate line, a data line crossing the gate line, and a TFT electricallyconnected to the gate line and the data line on an insulation substrate;forming a color filter layer on the switching member; forming aninorganic insulation layer on the color filter layer, the inorganicinsulation layer having a hole exposing a portion of the color filterlayer in correspondence with the TFT; and forming a pixel electrode onthe inorganic insulation layer.
 9. The method of claim 8, whereinforming the switching member comprising: forming a first metal patternincluding the gate line, a gate electrode of the TFT, and a storageelectrode on the insulation substrate; forming a gate insulation layeron the insulation substrate having the metal pattern formed thereon;forming a second metal pattern including the data line, and source anddrain electrodes of the TFT on the gate insulation layer; and forming aprotective layer on the insulation substrate having the second metalpattern formed thereon.
 10. The method of claim 9, wherein forming thecolor filter layer comprises: forming a red color filter, a green colorfilter and a blue color filter on the switching member; and forming astorage hole and a first contact hole on each of the red, green and bluecolor filters, the storage hole exposing a portion of the switchingmember in correspondence with the storage electrode, and the firstcontact hole exposing a portion of the switching member incorrespondence with the drain electrode.
 11. The method of claim 10,wherein forming the inorganic insulation layer comprising: forming aninorganic material on the color filter layer having the storage hole andthe first contact hole formed thereon; forming a hole and a secondcontact hole by patterning the inorganic insulation material, the holeexposing a portion of the color filter layer in correspondence with theTFT, and the second contact hole exposing a portion of the switchingmember in correspondence with the drain electrode; and forming a thirdcontact hole that exposes a portion of the drain electrode through theprotective layer.
 12. The method of claim 11, wherein the second contacthole is formed on the color filter layer coincidentally through the sameprocess as the third contact hole.
 13. A display device comprising: afirst substrate; a second display substrate facing the first displaysubstrate; a liquid crystal layer interposed between the first displaysubstrate and the second display substrate; and a column spacer disposedbetween the first display substrate and the second display substrate tomaintain a cell gap between the first display substrate and the seconddisplay substrate, wherein the first display substrate comprises: aswitching member including a gate line, a data line crossing the gateline, and a thin-film transistor (TFT) electrically connected to thegate line and the data line; a color filter layer formed on theswitching member; an inorganic insulation layer formed on the colorfilter layer, the inorganic insulation layer having a spacer hole formedthereon, which exposes a portion of the color filter layer incorrespondence with the column spacer; and a pixel electrode formed onthe inorganic insulation layer.
 14. The display device of claim 13,wherein the spacer hole is formed in correspondence with a position ofthe TFT.
 15. The display device of claim 13, wherein the inorganicinsulation layer comprises silicon nitride (SiNx).
 16. The displaydevice of claim 13, wherein the color filter layer has a storage holeexposing a portion of the switching member in correspondence with thestorage electrode.
 17. The display device of claim 13, wherein theswitching member comprises: a gate insulation layer formed on aninsulation substrate having the gate line formed thereon; and aprotective layer formed on the insulation substrate having the gateline, the gate insulation layer, the data line and the TFT formedthereon.
 18. The display device of claim 17, wherein a contact hole isformed through the protective layer, the color filter layer and theinorganic insulation layer to expose a portion of the drain electrode ofthe TFT.
 19. The display device of claim 13, wherein the secondsubstrate comprises: a black matrix covering the column spacer; and acommon electrode facing the pixel electrode.
 20. The display device ofclaim 19, wherein the second display substrate further comprises anovercoat layer for planarizing a surface of the second display substratehaving the black matrix formed thereon.